Internet web pages, online information, and media content such as audio, video, photographs, and the like are requested and delivered to wireless end users via computer network systems and wireless networks. Requests for the content are sent over a wireless network, to a wired network, and to a source server, processed, and the content is delivered to the end user via the wireless and wired networks. The source server can include origin or hosting servers which originally host the network content. Unfortunately, a single source server may not be able to serve a large number of concurrent requests for content. In addition, the requesting server may be distant geographically or network routing-wise from the source server. This can slow the process of delivering content to the point where users are dissatisfied, or abandon the request for content.
To address this problem, content delivery networks were developed. Content delivery networks cache content from a source server (a.k.a. origin server) for more rapid and reliable delivery to end users. A content delivery network may have many (or even thousands) content nodes distributed across a large geographic area (or network routing area) in order to provide faster, lower latency, and more reliable access to content for the end users regardless of their geographic or network location.
The content delivery process begins with a user submitting a request to a browser. When a user enters a uniform resource locator (URL), a domain name system (DNS) request is triggered and an IP address is retrieved. In a content delivery network structure, the domain name of the URL is translated by a mapping system into the IP address of cache node, which can have the content cached locally, to serve the content to the user. If the content is cached by the cache node, the cache node can directly service the end user's request. If the content is not cached in the cache node, or the content from the origin server is out-of-date or stale, the cache node can receive the content from the origin server and cache it. Once cached, the cache node can typically provide the content quickly.
When content is served to wireless devices, however, selecting a cache node to service the wireless device can be problematic. Likewise, the collection of measurements and metrics used to optimize a content delivery network can be affected by conditions within the wireless network. In other words, wireless network conditions (e.g., loading, internal structure, RF conditions, interference, etc.) can make the selection of a cache node, or the collection of measurements and metrics associated with the wireless device, difficult, unreliable, or poorly optimized.